The invention relates to an electropneumatic central unit for a commercial vehicle made up of modules with electrical and/or pneumatic components, wherein the individual modules are accommodated in module housings which are releasably connected to one another in a defined position and on which standardized pneumatic and electrical connections are arranged such that, when the module housings are connected, connections which are associated with one another and are arranged on opposing connection faces of the module housings form direct electrical and pneumatic connections with one another.
Nowadays, the pneumatic equipment in a modern commercial vehicle includes a plurality of electrical and/or pneumatic components, which are supplied with compressed air and also have electronic control systems. Most of these components are in the form of individual devices which can form different levels and combinations of equipment features when connected to one another. However, in this case, pneumatic lines and fittings of each device have to be individually supplied with compressed air. Furthermore, many devices of this type have their own electronic controllers and are each supplied with power and electrical signals via their own electrical lines. Furthermore, each of the controllers has to be individually equipped with circuits for voltage supply, for overvoltage protection, polarity-reversal protection, ESD protection, CAN interfaces, etc., and also has at least one microprocessor with a watchdog.
In addition to this, a plurality of electropneumatic components are also integrated in a common housing, with the result that only one controller and one pneumatic and electrical power supply are required. However, this procedure has the disadvantage that the number of variations grows depending on the level of equipment features. At the same time, repair costs are increased if the entire device has to be replaced in the event of a fault in one of the integrated systems.
DE 33 27 005 A1 describes a hydraulic distributor, which includes a plurality of individual blocks connected to one another. Each of these blocks has connection openings for a pressure line and a return line to the liquid reservoir. The connection openings, which are to be connected to one another, of adjacent individual blocks are arranged at suitable locations.
DE 199 07 667 C1 discloses a central unit in which various electropneumatic devices, for example an air dryer, a trailer control valve, a redundancy valve etc., are arranged separately from one another on a mounting plate, with the result that pneumatic and electrical lines running between the individual devices each have to be individually laid. In contrast, a connector strip, which is likewise fixed there, serves merely to receive pneumatic lines.
In the air-treatment apparatus according to US 2004/0145237 A1, a series of modules are connected to a controller by way of an intermediate piece, which serves exclusively to conduct electrical and pneumatic signals from the modules to the controller. A breakdown of this intermediate piece necessarily results in a breakdown of the entire system.
EP 1 400 702 A2 describes a pneumatic arrangement in which a plurality of maintenance modules, which are arranged next to one another, are connected to a control module via a common separate bus system. In this case, the bus system includes a plurality of bus modules associated with a respective maintenance and in the form of strip elements here. The bus system serves merely for the data interchange of electrical signals.
EP 1 081 389 A2 describes an electropneumatic device with electromagnetic valves which are arranged next to one another by way of separate branch blocks which are flange-connected to one another and pass on only pneumatic and electrical signals, but do not functionally influence or change the signals.
Accordingly, the above-mentioned prior art contains assemblies and modules which are formed separately from the actual functional modules and serve exclusively to divert or conduct electrical and pneumatic signals. However, this procedure requires a relatively high number of electrical and pneumatic connections, which are to be connected to one another, when the modules are joined. This has a disadvantageous effect on the frequency with which faults occur. In addition, a breakdown of an assembly which serves exclusively to pass on electrical and/or pneumatic signals results in a breakdown of the entire system.
In contrast, the object of the present invention is to form a central unit which is provided for a commercial vehicle in such a way that it has greater availability.
According to the invention, this object is achieved by an electropneumatic central unit for a commercial vehicle, which is made up of modules with electrical and/or pneumatic components, wherein the individual modules are accommodated in module housings releasably connected to one another in a defined position and on which standardized pneumatic connections and electrical connections are arranged such that, when the module housings are connected, connections which are associated with one another and are arranged on opposing connection faces of the module housings form direct electrical and pneumatic connections with one another. The central unit is constructed without modules which serve merely to conduct pneumatic and/or electrical signals between modules.
The present invention is advantageous in that no further additional connection lines are necessary since the electrical and pneumatic connections are automatically produced by the connection of the individual modules, for example by plug and/or contact connections, which engage with one another when the module housings are joined to one another. This results in extremely favorable production and manufacture of such a central unit.
In the present invention, continuous pneumatic channels, for example pneumatic supply channels, may be formed, which channels only need to be connected to a central compressed-air source from one side or in the case of which an air-conditioning unit itself represents an integrated module of the central unit and/or connected-through electrical lines. Since the connections are located directly on the connection faces between the module housings, which are firmly connected to one another during operation, very economical solutions are possible. Furthermore, modules of this type having standardized electrical and pneumatic connections may be used to produce a large variety of variants of electropneumatic central units. Last but not least, a central unit of this type can be repaired in a very cost-effective manner since only the defective module has to be replaced in each case. In this way, a compact central unit is created, which can be treated like an individual module.
In order for the electrical and pneumatic connections to be made, the module housings have to be connected to one another in a defined position, the electrical and pneumatic connections which are associated with one another have to be standardized, that is to say have the same connection dimensions in relation to the respective form of energy—electrical or pneumatic—and, in the installation position, be aligned with one another or make contact with one another such that they are aligned. Similarly, the connection faces of the modules have to be designed such that the modules can be fixed to one another in any desired combination and preferably also in any desired order and at the same time produce conductive electrical connections or pressure-tight pneumatic connections.
The invention proposes constructing the central unit without modules serving merely to conduct pneumatic and/or electrical signals between other modules.
Modules which serve merely to pass on electrical and/or pneumatic signals are to be understood, for example, as modules such as the separate intermediate piece according to US 2004/0145237 A1, the common separate bus system according to EP 1 400 702 A2, or the branch blocks which are flange-connected to one another according to EP 1 081 389 A2. Avoiding such modules reduces the possibility of the entire system breaking down in the event of such a module breaking down, and this has a positive effect on the availability of the central unit. A further result is a central unit in which signal-conducting functions are implemented by the functional modules themselves, with the result that the omission of purely conductive modules is accompanied by savings in electrical and pneumatic contact points between the functional modules. This likewise reduces the frequency with which faults occur.
A person skilled in the art will be aware of several embodiments which meet these requirements and of which some are described in the subclaims.
In order to connect at least two modules to one module, the module housings of at least some modules particularly preferably have pneumatic and electrical connections on at least two different connection faces. If at least the connection faces of the module housings are furthermore of planar design, the central unit can be constructed from a plurality of modules which are fixed to one another in series, with a termination plate then being provided for the pneumatic and electrical connections of a connection face of a first module and/or of a last module. The termination plate closes the pneumatic connections.
In this case, the electrical connections include, for example, contact areas which are arranged on the connection faces of the module housings and/or male/female connector strips which can be plugged into one another. Power supply lines, signal lines and/or data buses, which extend at least through a portion of the central unit, are formed by the electrical connections of the individual modules.
The pneumatic connections are preferably likewise arranged on the connection faces of the module housings, with the pneumatic connections being formed, for example, by pneumatic connections being contact-connected in a sealed manner and/or being plugged into one another.
The module may be connected to one another by tie rods and may have centering areas.
At least one module may be formed by an air-conditioning unit which includes an electronic controller implementing the function logic of at least some of the other modules and actuating them via the electrical connections. In addition, at least one module can include only one central controller and only connect-through pneumatic signals
Furthermore, at least some of the modules may have, in addition to the connections for forming electrical and pneumatic connections with one another, additional electrical and/or pneumatic connections for external signals.
A continuous pneumatic channel, for example a ventilation channel, is then formed by a connection of at least some modules, to which channel an external, common sound absorber can be connected.
The construction of a central unit from a plurality of modules with electrical and/or pneumatic components is explained by the following description of one exemplary embodiment of the invention.